The present invention pertains to mechanical presses, and, in particular, to a flywheel and clutch assembly used to selectively couple a rotating flywheel with a rotatable press crankshaft.
Mechanical presses such as straight side presses and gap frame presses for stamping and drawing operations include a frame having a crown and bed and a slide supported within the frame for reciprocating motion toward and away from the bed. The slide is typically driven by a crankshaft having a connecting arm connected to the slide, to which is mounted the upper die. Rotation of the crankshaft moves the connecting rods to effect straight reciprocating motion of the slide. The lower die is conventionally mounted to a bolster which, in turn, is connected to the bed. Such mechanical presses are widely used for blanking and drawing operations and vary substantially in size and available tonnage depending on their intended use.
The primary apparatus for storing mechanical energy in a press is the flywheel. The flywheel is usually mounted at one end of the crankshaft and connected by a belt to the output pulley of a motor such that when the motor is energized, the massive flywheel rotates continuously. The flywheel and flywheel bearing are normally axially mounted on either the driveshaft, crankshaft, or the press frame by use of a quill. The main drive motor replenishes the energy that is lost or transferred from the flywheel during press operations when the clutch engages the flywheel to transmit rotary motion of the flywheel to the crankshaft. During engagement of the clutch, the flywheel drops in speed as the press driven parts are brought up to press running speed.
In some presses, a flexible clutch plate with a drive disk is attached to the flywheel. A driven disk of the clutch mechanism is attached in a rotationally fixed manner to the crankshaft and may be selectively operated to engage the drive disk of the flywheel, thereby transferring rotational energy to the crankshaft. An improved design disclosed in U.S. Pat. No. 5,370,045 employs a flexible clutch plate between the drive disk and the flywheel, but the drive disk is mounted to the clutch plate to permit radial thermal expansion of the disk during use.